1. Technical Field
Example embodiments generally relate to a fixing device, an image forming apparatus, and a fixing method, and more particularly, to a fixing device for fixing a toner image on a recording medium, an image forming apparatus incorporating the fixing device, and a fixing method for fixing a toner image on a recording medium.
2. Background Art
Related-art image forming apparatuses, such as copiers, facsimile machines, printers, or multifunction printers having two or more of copying, printing, scanning, facsimile, plotter, and other functions, typically form an image on a recording medium according to image data. Thus, for example, a charger uniformly charges a surface of a photoconductor; an optical writer emits a light beam onto the charged surface of the photoconductor to form an electrostatic latent image on the photoconductor according to the image data; a development device supplies toner to the electrostatic latent image formed on the photoconductor to render the electrostatic latent image visible as a toner image; the toner image is directly transferred from the photoconductor onto a recording medium or is indirectly transferred from the photoconductor onto a recording medium via an intermediate transfer belt; finally, a fixing device applies heat and pressure to the recording medium bearing the toner image to fix the toner image on the recording medium, thus forming the image on the recording medium.
The image forming apparatuses employ fixing devices of various types, such as a roller type, a film type, and an induction heating type.
For example, the roller type fixing device may include a fixing roller heated by a heater and a pressure roller pressed against the fixing roller to form a fixing nip therebetween. As a recording medium bearing a toner image is conveyed through the fixing nip, the fixing roller and the pressure roller apply heat and pressure to the recording medium, melting and fixing the toner image on the recording medium.
The film type fixing device may include a fixing film and a heater contacting the fixing film as disclosed by JP-S63-313182-A and JP-H1-263679-A. For example, a pressure roller presses a recording medium bearing a toner image against the heater via the fixing film. As the fixing film sliding over the heater conveys the recording medium, the fixing film heated by the heater heats the recording medium.
The induction heating type fixing device may include a fixing sleeve incorporating a heat generation layer, a fixing roller disposed inside the fixing sleeve, and a pressure roller pressed against the fixing roller via the fixing sleeve to form a fixing nip between the fixing sleeve and the pressure roller. The heat generation layer of the fixing sleeve generates heat by induction heating. As a recording medium bearing a toner image is conveyed through the fixing nip, the fixing sleeve heats the recording medium.
A contact member that contacts the recording medium, that is, the fixing roller, the fixing film, the fixing sleeve, or the pressure roller described above, may receive contaminants, such as unfixed toner and paper dust, from the recording medium. If the contaminants adhere to and accumulate on the contact member, the contaminants may be transferred onto a recording medium conveyed through the fixing nip. To address this circumstance, a roll type cleaning web may contact the contact member to wipe the contaminants off the contact member as disclosed by JP-2000-321914-A and JP-2011-215587-A. The cleaning web is reeled to bring a fresh portion of the cleaning web into contact with the contact member constantly. Hence, the contaminants do not accumulate on the cleaning web.
Since the cleaning web is reeled constantly, it is requested to reduce consumption of the cleaning web. However, it may be difficult to reduce consumption of the cleaning web because reduced consumption of the cleaning web may degrade cleaning performance to clean the contact member. Accordingly, the unclean contact member may damage the toner image on the recording medium, resulting in degradation in quality of the toner image formed on the recording medium.